A note on Develop has further indications that Battlefield 3 will not be released through Steam, as speculation mounts that DICE's military shooter sequel will not appear on Valve's download service. They quote a comment from a report from financial research firm Baird based on a meeting with GameStop: "The upcoming EA title Battlefield 3 will be sold as a download through GameStop, but not through Steam," Baird says GameStop executives told them. "Given Steam's dominance – and insistence on users downloading a Steam client application – publishers are likely to be receptive to a competitive alternative." Thanks Computer and Video Games.

I will note however that no one can explain Crysis 2 disappearing. It's not exactly lighting the sales charts on fire, I'm not sure why it would be pulled which would suggest some form of distribution dispute.

It was pulled on the exact same day that the first map pack DLC became available. This DLC was not available on steam, I believe you had to purchase it through the EA store, or directly from EA in some way. Steam wasn't getting their cut for that content so they pulled the game.

Steam removed the game because gamers could not purchase the DLC through steam. EA probably knew this was going to happen and didn't care or felt that it would be better to maximize profits from the DLC rather than get future sales of the core game through steam.

And judging by how companies sell their DLC they are probably right that they did not stand to make any significant dollars from selling the core product in the future that would offset the extra fees paid to valve to sell the DLC through steam.